In a cellular communication system, a plurality of wireless base stations are typically used to provide communication services to mobile users within the system. Each base station will often service multiple users within a coverage region or cell associated with the base station. To allow multiple users to share a base station, a multiple access scheme is typically employed. One multiple access technique that is becoming increasingly popular is code division multiple access (CDMA). In a CDMA-based system, a plurality of substantially orthogonal codes (usually taking the form of pseudo-random noise sequences) are used to spread spectrum modulate user signals within the system. Each modulated user signal has an overlapping frequency spectrum with other modulated user signals associated with the base station. However, because the underlying modulation codes are orthogonal, each user signal can be independently demodulated by performing a correlation operation using the appropriate code.
In at least one CDMA-based cellular standard, each of the base stations in a system maintains a pilot channel that continuously transmits a predetermined pilot sequence. These pilot signals may then be utilized by users in the system to perform, for example, channel estimation, handover operations, and/or other functions. Pilots from different base stations are sometimes distinguished by a time offset between individual base stations. Thus, a pilot having a specific time offset (from, for example, an absolute time reference) will be known to have come from a corresponding base station. As can be appreciated, a communication device operating within a cellular-based system implementing CDMA will often receive overlapping communication signals from a variety of different sources (e.g., other base stations, etc.). These overlapping signals represent interference in the system and can degrade system performance. Any reduction in such interference, therefore, may enhance the quality of the corresponding communication link or increase the capacity of the system. Thus, there is a general need for methods and structures to reduce interference in cellular communication systems.